Smaller lungs, narrower airways, slower airflow: patients successfully treated for tuberculosis have a reduction in their respiratory capacity, thereby reducing their quality of life.
- Decreased access to tuberculosis care in 2020 led to a global increase in tuberculosis cases, including in France. Today, an estimated 155 million people have survived this infectious disease.
- According to this new study, which will be presented at the next ESCMID world congress, these survivors have lifelong consequences: smaller lungs and narrower airways with slower air flow.
- “This legacy of tuberculosis has been neglected for too long and it is essential that it is recognized,” says the doctor-researcher. “This can cause shortness of breath which can affect the ability to work, carry out daily activities [ce qui peut] reduce quality of life.”
“Tuberculosis remains a major infectious disease globally, with more than 10 million cases, leading to 1.4 million deaths each year.”, indicates the Pasteur Institute. It is caused by bacteria, Mycobacterium tuberculosisbetter known as Koch bacilli, and is transmitted by air.
In new research to be presented at the ESCMID (formerly ECCMID) World Congress in Barcelona, Spain, scientists show that even patients successfully treated for the disease have lifelong aftereffects.
Tuberculosis: 155 million survivors worldwide
Since Covid-19, the number of new TB diagnoses has increased, with some 7.5 million people diagnosed globally in 2022, the highest figure since surveillance began in 1995, according to the WHO global report 2023 on tuberculosis. In question ? A sharp decline in access to TB care in 2020, which only partially recovered in 2022, paving the way for bacteria to spread. While sub-Saharan Africa and South-East Asia are the most affected regions, there is also an increase in diagnoses in low-incidence countries such as the United Kingdom. According to provisional data from the UK Health Security Agency, there were 4,850 new diagnoses in England in 2023, an increase of more than 10% compared to 2022 which had 4,380 diagnoses. France is no less spared with 4,728 cases recorded last year compared to 4,306 in 2021, an increase of 9.8%, according to Public Health France.
To date, scientists estimate that approximately 155 million people are alive thanks to the successful diagnosis and treatment of the bacterial infection. For the principal investigator From this new work, Dr Sharenja Ratnakumar, of St George’s University of London, it is clear that “post-tuberculosis lung disease is an underestimated global challenge”. “Until now, the focus has been on treating acute tuberculosis, but even when treatment is successful, individuals can be left with significant lung damage.”, he adds.
Post-tuberculosis: “an increased risk of cardiovascular and respiratory diseases”
In a recent meta-analysis, Dr. Sharenja Ratnakumar and colleagues pooled data on 75,631 people from 15 studies conducted in 17 countries with varying levels of TB incidence. Among them were 7,377 tuberculosis survivors, aged 11 to 65. Four measures of lung function were used here:
- forced vital capacity (FVC), i.e. the volume of air that can be forcefully exhaled in a single breath;
- forced expiratory volume in 1 second (FEV);
- the FEV/FVC ratio;
- the FVC as a percentage of the predicted value, which compares the volume to that of the average healthy person of the same age, sex and height.
This revealed that compared to healthy subjects, tuberculosis survivors had significantly lower results, especially for forced expiratory volume in 1 second. “FEV1 was 230 milliliters lower than healthy controls and FVC was 140 milliliters lower, specifies the doctor-researcher. A decrease in FEV1 of 100 milliliters is considered clinically significant and is associated with an increased risk of cardiovascular and respiratory diseases.”
65% higher risk of airway obstruction after tuberculosis
Taken together, these findings indicate that tuberculosis survivors have smaller lungs and narrower airways with slower airflow. Clearly, these people take smaller breaths each time they breathe, and therefore have more difficulty responding to increased ventilatory demands, such as during a sports session. These people therefore have a 65% higher risk of airway obstruction than others.
“This legacy of tuberculosis has been neglected for too long and it is essential that it is recognized,” says the expert. This can cause shortness of breath which can affect the ability to work, carry out daily activities [ce qui peut] reduce quality of life.”
“Our study also provides compelling evidence that long-term care of people with post-tuberculosis lung disease should be an explicit component of the WHO strategy to end TB“, he concludes.